For many years those scientists working in support of the medical and dental professions have sought readily assimilable organic polymers that would be useful as surgical repair materials. One application for such materials is in dry socket therapy. After the removal of a third molar, the cavity that is left in the mouth by the extraction of the third molar heals slowly. If an assimilable prosthesis were available, it could be useful for insertion in the socket, to help the healing process.
Polylactic acid has been suggested for use in the past as a surgical repair material. Kulkarni et al., Arch. Surg., Vol. 93, November, 1966, pages 839-843. Polylactic Acid for Surgical Implants. Kulkarni et al., J. Biomed, Mater. Res., Vol. 5, pp. 169-181 (1971), Biodegradable Poly (lactic Acid) Polymers. The use of polyglycolic acid has also been suggested, U.S. Pat. No. 3,463,158. Filaments made from polylactic acid and related materials are suggested in Japanese published patent application No. 2743 (Showa 41-2734), 1966, and U.S. Pat. No. 3,531,561. The hydroxy carboxylic acids, and particularly the alpha hydroxy carboxylic acids, are of particular interest as biodegradable polymers because they may undergo hydrolytic scission to form metabolites normal to the body.
Unfortunately, these polymers, while biodegradable and assimilable, are naturally hydrophobic. Accordingly, when an attempt is made to use a porous shaped body of polylactic acid, for example, in dry socket therapy, blood does not wet the implant, and consequently a clot forms that surrounds the implant and granulation is hindered and retarded rather than helped.